Full Version: Boolean not working

Show messages:  1-14  15-31

Hi Billabong, can you please also post the .3dm model file that you are showing in the video?

It's pretty hard to figure out what is going on without being able to examine the actual geometry.

Thanks, - Michael

---

Sure thing. Sorry about that. Just a quick note, this happens every time I create a patch from existing faces.

Attachments:
patch_problem.3dm

---

Hi Billabong, you generally want to make things more by intersecting parts that push through each other rather than going around and filling in patches like this.

If you do want to fill in using Network, it will be tough to do it on edges that are meeting up a little loosely like you have here.

That's because to Join the new patch needs to have its edges match up close enough to the original edges, when you edit the curves that's basically moving stuff away from where Join will want it at. But just using Network without moving pieces isn't going to help because the surface that network generates will be an average anyway where things don't touch exactly.

Another complicating factor is a couple of micro edges in this area:





If you turn on surface control points on your Network, you'll see that even though the shape is very nearly planar, it's got a bunch of control points all sliding and skewing along like this:



This is not that great because you generally want surface control points to naturally follow the surface shaping and boundary details come from trim boundaries instead of baked directly into the surface structure.

I'll take a look at doing some repair work to simplify the edges.

- Michael

Image Attachments:
micro_edge1.jpg  micro_edge2.jpg  networkcontrolpoints.jpg 

---

Hi Billabong, some of the surfaces in here are a little odd, like this strip here:







That looks like it wants to be an extrusion that is trimmed but instead it's something that's surfaced directly between 2 long curves, unlike an extruded surface all of the surface control points are not all in one single direction there is kind of a skew between them in some areas.

I mean it's still a surface but it's more complex and less accurate than an extruded surface.

- Michael

Image Attachments:
extrusion1.jpg  extrusion2.jpg  extrusion3.jpg 

---

Hi val2
>I looked at it in Cad Assistant???
How do you open a .3dm file in "Cad Assistant"? I've read about opening Nurbs files but I don't understand how to do it.

https://www.opencascade.com/products/cad-assistant/
Additional mesh file formats import is supported with help of Open Asset Import (COLLADA, 3DS, FBX, BLEND) and openNURBS (3DM) libraries.

Well, I think that's way beyond my capabilities. But it may be of interest to some people.
https://github.com/mcneel/opennurbs

---

Zooen,
I import and export with STEP.


Basic functionality is provided by XDE component of Open CASCADE Technology (OCCT). The program supports the following file formats:

STEP (AP203, AP214 and AP242) — ISO 10303 standard for product data representation and exchange among CAD systems (ASCII format). Supported data: shape geometry, assembly structure, colors, names, validation properties, file information, dimensions and tolerances (semantic and tessellated PMI).
IGES (5.1 and 5.3) — vendor-neutral format for data exchange among CAD systems (ASCII format). Supported data: shape geometry, colors, top-level object names, file information.
glTF — API-neutral runtime asset delivery format (ASCII or binary), commonly supported by modeling systems and game engines. Supported data: shape geometry (triangulation), assembly structure, PBR metallic-roughness materials with texture maps, names.
XBF — BinXCAF, which is a binary persistence format for universal XCAF document structure used by OCCT. Format accumulates persistence of various data which can be imported from other files formats like STEP, IGES, ACIS, glTF, etc.
BREP — ASCII persistence of shape Boundary representation used by OCCT with open specification. Supported data: shape geometry and assembly structure (defined by nested compounds, without names).
OBJ Wavefront — format for 3D assets exchange commonly supported by modeling systems and game engines (ASCII format). Supported data: triangulation and quads, plain list of named groups, common materials with texture maps.
VRML or WRL — ISO 14772 virtual reality modeling language (ASCII format). Supported data: triangulation, assembly structure, colors, names.
Additional mesh file formats import is supported with help of Open Asset Import (COLLADA, 3DS, FBX, BLEND) and openNURBS (3DM) libraries.

---

@Michael,
This is becoming an absolute nightmare. I totally understand that its stemming from my lack of knowledge to achieve this in the proper fashion, but there isn't a lot of information out there on how to achieve good clean results with this method, unless you know of some tutorials or courses that go over this type of thing. I've watched almost all of Kuechmeister Swagger videos and he makes using networks and lofts look relatively straight forward, but its proving out that, that's not the case at all.

---

Hi Billabong,

It sounds like most of the problems are related to using MoI as a surface modeller rather than a solid modeller. In other words, trying to make a bunch of individual surfaces and stitch them together rather than making simple solids and using those as components or cutters.

Surface modelling is tricky, but Kuechmeister Swagger is really good at it and so makes it look easy. Like how professional athletes make scoring goals look easy.

For organic shapes that require surfacing there are some more tutorials here:

http://www.k4icy.com/tutorials.html

However, maybe starting over and sticking with solids for a while would help. Looking at your model it seems like much of it could be made by adding and subtracting simple solids and then filleting to blend them together.

- Peer

---

@pressure,
Your absolutely right, its just that surface modeling is what really interested me about Nurbs modeling to begin with. Solid modeling can be done in most 3d programs now with Booleans, so theres not much difference there, but regardless of that, I totally understand what you mean.
I have actually tried to go on k4icy.com tutorials, but when you click on any of the links to view it. None of the images show up anymore. All the links to the images are broken. So without them the tutorials are pretty much useless for me.

---

Hi Billabong,

Luckily MoI can do both surfaces and solids in the same environment and has operations that blend the two like using a surface as a boolean cutter for a solid.

Several of the problems that have come up sound like they stem from using Network when it's not the best tool for the job. Like when Michael said above that "That looks like it wants to be an extrusion that is trimmed but instead it's something that's surfaced directly between 2 long curves..." or also the nearly-planar surface that he pointed out.

So, instead of surfacing everything you could use solid operations for most things, and only surface when it's required. For the model you've been posting most if it could be done with solid operations from primitive solids like cylinder, sphere, revolve, or extrusion. For airplanes and cars there's lots of surfacing. But even when doing surfacing life can still be made easier by putting together solid "components" from the surfaces and then booleaning those together.

I understand you're already doing that, but the simpler each component is, the easier it will be to troubleshoot rather than looking for a needle in a haystack when trying to put a bunch of surfaces together at the same time.

For micro edges there's a plugin tool for finding them:

http://moi3d.com/forum/index.php?webtag=MOI&msg=11271.13

The problem with surfacing is really that NURBS is a system capable of extreme accuracy. That sounds good, but it also means that it's intolerant of the slightest inaccuracy.

If you make solids that push through each other a little bit (overlap in 3D space) and then boolean them the overlap gives some slack to the boolean algorithms when figuring out how to combine the shapes.

Even when surfacing, it's best to use large surfaces that intersect so that the intersection can be used as the trim / edge. That get's rid of the accuracy problem by guaranteeing that the 2 surfaces meet along a common curve.

But, if you are going to build things up from surface patches you will need to work to the same in-human level of accuracy that NURBS entails. Like in your video, you move around some curve endpoints to get them to match up. That doesn't mean that the curves match up with the rest of the 3D object. And those tiny imperfections that are small on a human scale are actually large on a NURBS scale, so the software has no choice but to decide that the surface patches are too far apart to join.

- Peer

---

Hi Billabong,

Re:
> I have actually tried to go on k4icy.com tutorials, but when you click
> on any of the links to view it. None of the images show up anymore. All
> the links to the images are broken. So without them the tutorials are
> pretty much useless for me.

There is something weird about photos loading on those forum posts. I tried viewing:

http://moi3d.com/forum/messages.php?webtag=MOI&msg=6706.1

And the first time I saw generic icons for each of the photos, but after refreshing a few times the images loaded.

So maybe try refreshing the pages a few times to see if that gets the photos to load.

- Peer

---

for me it's appearing absolutely normally...first download since 2014! ;)
as it's a long page...and if you have not a speed connection maybe this explains that...

---

Mayo takes over the relay of Cad Assistant!
https://github.com/fougue/mayo

---

Hi Billabong,

re:
> I've watched almost all of Kuechmeister Swagger videos and he makes using networks
> and lofts look relatively straight forward, but its proving out that, that's not the case at all.

Those techniques are for an advanced (and rather finicky) type of organic shape modeling for things like car bodies that don't have any straight line or planes in them at all. That area of NURBS modeling has a high learning curve and really it can be easier to do these types of forms in a poly modeling program using subd smoothing instead. NURBS modeling has it's greatest strength and lowest learning curve when doing mechanical shapes largely defined by 2D profile curves and using booleans.

For mechanical shapes you don't want to use those methods, for mechanical shapes you want a line to be a line and a planar area to be a plane surface instead of glommed together pieces with rebuild and Network on everything.

You'd probably be better off if you didn't see those particular tutorials until some time later on.

- Michael

---

Hi Billabong, here is a version with the hole you were trying to patch filled in.

I put in a plane through that area and reconstructed the vertical surfaces around the hole to extend past the plane and get trimmed by the plane:



- Michael

Attachments:
patch_problem2_3dm.zip

Image Attachments:
planar_filled.jpg 

---

Message 11322.30 was deleted

---

Free Onshape online can open a Moi 3DM format !
https://cad.onshape.com
You can of course use it as a converter! ;)

For import a file press "+" left Bottom page!

OnShape is a monster! :)

---

Show messages:  1-14  15-31